Pump



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M. H. SMITH Aug., m, mi.

PUMP

Filed March 18, 1940 2 Sheets-Sheet l Vial ' INVENToR TIYRON H. SMITH ATTORNEYS Aug. l2, 1941.

Filed March 18, 1940 M. H. SMITH PUMP 2 Sheets-Sheet 2 NVENTOR N RON Hamm Fig. 4 Y

miv/VMM 81W A I'TORNEYS Patented Aug. 12, 1941 UNITE il ST vS PATENT OFFICE rum Myron H. Smith, New Hartford, N. Y., assigner to D. B. Smith a Company Inc., Utica, N. Y., a

corporation of New York 4 Claims.

My present invention relates to a pump which is especially adapted for use with a knapsack sprayer.

The purpose of this invention is to provide a new and improved. pump which while especially useful as a part of a knapsack sprayer is not limited in its use to that place but as will hereinafter appear may be used to advantage in other places where a manually operated reciprocating pump is required.

A further purpose is to provide a pump of the class described which is of new and improved construction, economical in manufacture and assembling. and very durable in use, not liable to get out of order, and especially efficient. In a knapsack sprayer the receptacle is carried upon the back of the man using it and the pump, of a construction as shown in the drawings and hereinafter described in detail, is mounted in the receptacle and its upright barrel is reciprocated vertically by means of a hand-operated lever which projects from one side of the receptacle near its lower end, and is just above said fulcrum point pi'voted` to the lower end of the connecting rod, the upper end of which is pivotally secured to the upper end of the reciprocating barrel. It will be seen from the above brief description that the body of the man carrying the knapsack receptacle stands the strain of imparting the up and down motion to the pump barrel and accordingly it is highly desirable that the pump barrel operate as easily and efficiently as possible so that the required amount of work may be done by the pump without subjecting the mans body, which carries the knapsack, or his arm that reciprocates the pump, to any greater strain or jerking movement than is absolutely necessary.

A further purpose is to provide a pump and a knapsack sprayer where a closed well is provided projecting downwardly irom the bottom of the receptacle into which well projects the plunger at the lower end of the reciprocating pump barrel and with the mechanism, specically the well, provided with an aligned upwardly extending guide having perforations at its lower portion through which when the plunger is raised the. water from the receptacle will pour into the well and' thenbe driven upwardly through the plunger check valve on the downward stroke of the pump barrel.

A further purpose is to provide in a device of the class indicated a preferably one-piece or integral well and plunger guide so that the plunger may be easily drawn up and pushed down Awithout' resistance or obstruction other than claims herein.

Fig. 1 is a Vertical sectional View on a reduced scale of 'a knapsack sprayer provided with a pump embodying, this invention, the section being taken along the broad axis ofthe sprayer and with, the upper part of the barrel and its attached parts shown in section but with the greater part of the barrel and especially its' lower portion shown in side elevation, the pump barrel being shown in the position it occupiesl when near the lower limit of its downward movement,

Fig. 2 is' a right hand side elevation of the knapsa'ck sprayerV shown in Fig. 1 but with the 'parts in the position they occupy when the pump reland its plunger are close to theV lower limit ofy their travel'.

Fig. 4 is a side elevation of the well and plunger guide andof the lower portion of the pump barrel' with the barrel raised to about its normal upward position so that the liquid from the receptacle canv easilypour through the slots in the plunger guide into the well.

Fig. 5 is a separate side elevation of the well andthe plunger guide. 1 Fig. 6'is `a separate side View of the lower'portion ofthe pump barrel and its plunger and with the lower part of the larger diametered portion of the pump barrel shown.

Fig. 7 is a horizontal transverse sectional View on line 'l-T of Fig. 4.

Fig. 8 is a similar sectional view on line 8--8 of Fig. 3.

Views 4to 8 are drawn to the same scale as Fig. 3, that is, natural or full size.

Referring to the drawings in a more particular description it will be seen that the pump mechanism embodying this invention is illustrated in connection with a knapsack sprayer where the tank or receptacle l 0 is preferably kidney-shaped in crosswise section, so as to fit more or less to the back of the man carrying and using the sprayer. This tank is conventionally constructed of the proper sheet metal and has its bottom II set up into the lower part of the receptacle a considerable space from the lower edge of the tank so as to provide an open-bottomed chamber I2 at its lower end for the purpose of providing space for the safe downward projection of the well I3, which projects down from the level of the bottom Ii. As a protection against any accidental exterior strain against the bottom of the well I3 there is preferably provided a cross brace I4 extending from front to back of the skirt portion of the metal of the tank toward the bottom of the chamber i2 and preferably closely supporting the bottom imperforate end of the well I3.

Preferably there is formed integral with the side wall of the well I3 an upwardly extending plunger guide I5 so that the side wall of the preferably circular guide I5 is in perfect alignment with the circular side wall of the well I3. Mechanically these two parts might be formed separately and connected but preferably the two parts will be formed of one short length of seamless brass tubing so that the side walls of the two parts will be in perfect alignment and of the same diameter, in order, as already suggested, that the pump plunger I6 may readily pass up and down from one part to the other of said well and guide without having to meet any resistance other than that of the work being performed or the friction between the parts in contact. Preferably the well is supported and secured to the bottom II of the receptacle by means of an annular bracket l1 of angle iron form when seen in vertical section, so that the Vertical web I8 of said bracket closely encircles the upper portion of the well i3 and is permanently and securely fastened thereto as by brazing or the like. The outwardly extending web I9 of this bracket rests down into the pocket formed by the metal of the bottom adjacent the well aperture formed in said bottom, being offset or stepped downwardly slightly so that as appears in the drawings (see Figs. l and 3) the upper surface of the web I9 will be certainly no higher than the upper surface of the bottom ll of the receptacle I0. The web I5 is permanently secured to the bottom II by a liquid-tight joint.

As the sprayer is illustrated the pump mechanism is located in the right hand end of the receptacle, that is the pump cylinder 20 is reciprocatingly located in the right hand end of the receptacle and the operating lever 2l and the connecting link 22 extending from near the bottom of said lever to the cap 23 at the top of said barrel are immediately outside the right hand end of the receptacle of the sprayer. This right hand location of the pump is for the convenience of the ordinary right handed man, so that the operators right hand and arm will do the physical work of moving the pump while the operators left hand holds and controls the spray nozzle (not shown), to which the length of hose 24 extends from the liquid outlet 25 in the cap 23.

Conveniently a strong strap 26 is rigidly fastened to the right hand end of the receptacle close to its bottom and said strap has an outwardly offset return loop 21 towards the left as the parts are seen in Fi-g. 2, and through the double layers of said loop 21 is set a pivot pin 28 to which is pivotally connected the lower end of the operating lever 2|. The upper end of this lever is conveniently covered with a length of thick rubber hose forming a convenient and comfortable handle 30 for the operator of the sprayer to work the pump. A little way up from the pivot pin 28 the operating lever ZI is provided with a hole 3l through which outwardly projects the outwardly bent horizontal lower portion 32 of the strong stiff connecting rod 22. The upper end of this connecting rod is bent inwardly at right angles and extends into a horizontal hole 34 formed in the outer or right hand portion of the cap 23. A split pin or similar device 35 secured to the inner end of the upper horizontal portion of the connecting rod normally secures the connecting rod from accidental disconnection from the cap 23 of the pump barrel 20 but in an obvious manner allows this end of the connecting rod to be detached from the pump barrel when occasion requires. The cap 23 consists of a disc portion 36 closing the upper end of the pump barrel 2B, with said cap securely attached to the said barrel as by said disc portion being provided with a downward hanging annular flange 31 which is preferably permanently secured to the outer surface at the upper end of the pump barrel as by brazing or the like. From the right hand or outer side of the cap 23 as the parts are shown there extends upwardly a loop portion 38 in which is provided the horizontal hole 34 already mentioned for the pivotal connection of the connecting rod to the said cap. In the left hand half of said cap there is provided an upwardly extending enlargement 39 in which is provided a horizontally arranged port 4I] connected at its inner end to a vertically arranged port 4I opening to the inside of the pump barrel 20. To the lower end of this port 4I is attached the upper end of the liquid pipe 42 which goes down inside the large portion 20 of the barrel nearly to its lower end and serves in the way of such pumps to conduct the spray liquid from the lower part of the barrel up to the port 4I and the outlet port 40 while the chamber 43 of said barrel 20 surrounding said pipe 42 serves as a chamber for compressed air whereby in the way common to such pumps after a few strokes are taken a practically continuous stream of spraying liquid can be sent out from the pump.

The receptacle IG is provided at its top with a cover, the right hand portion 44 of which is permanently and very rigidly secured to the top of the tank or receptacle I0 while the central and left hand portion 45 of the cover is detachable for the purpose of replenishing the liquid of the receptacle and cleaning out the inside of the receptacle when required. This right hand rigid portion 44 of the top is provided with an aperture through which the pump barrel 20 projects and about the periphery of this aperture there is provided an upstanding collar 46 preferably having several inwardly extending annular beads 41 which serve as the immediate guide for the upper portion of the pump barrel, but without giving any such long contact between the collar and the pump as would induce decided friction.

The pump barrel already denoted by the numeral 20 is preferably formed of a length of seamless brass tubing and it has rigidly secured to its lower end an extension 48 which is rigidly secured in axial alignment with the larger portion 2U and is also preferably a length of seamless brass tubing. This extension is of appreciably smaller size than the main barrel portion 20 for a purpose that will be hereinafter described. On the other hand the well I3 and the plunger guide I5 are of a diameter intermediate the diasta, 14e

arneter of the barrel extension 48 and the main barrel Z. On the inside of the lower end of the barrel extensionV 48 there is rigidly and permanently secured a disc which at its central portion is provided with an upwardly extending tubular portion 50 which is screw-threaded at its interior aperture. A rubber plunger cup l of the conventional plunger cup shape as shown in Fig. 3 has its skirt portion of a size to snugly iit the inside of the well i3 and the plunger guide I5 while the upper end disc portion 53 of said plunger cup fits exteriorly against the inner wall of the lower portion of the extension 48 of the barrel while the upper surface of the disc portion 53,' of the plunger cup bears directly against the flat lower side of the disc-like closure 49. The disc 53 of the plunger cup is provided with a relatively large hole through which projects the threaded smaller diametered portion of the plug 54', while the enlarged head of the said plug provides an upwardly facing shoulder 55 adapted to bear against the lower face of the disc portion 53 of the plunger cup adjacent the apertures in said plunger. The portion of said plug for some distance above the shoulder 55 is screw-threaded to engagethe interior` screw-threading upon the tubular portion 50 of the disc 49.

Upwardly through the enlarged head oi plug 54 there is provided a central port 56. About half way up through this head there is provided a valve seat 5l and above said seat the centralhole extending up through said plug is of appreciably larger diameter than the said seat and than the diameter of the valve ball 58 which normally seats downward against the seat 5l. The ball 58 tends to seat down on said valve seat and so form a check valve of obvious form, but in order to be sure that this check valve operates properly I provide aA small light coiled spring 59 coiled about a small stem 65.. The lower end of this stem is permanently secured to said ball 58 and projects upwardly through the central passage in the plug 54 and has its upper end guided and held centrally in position by extending through a central hole provided in a bridge piece tl suitably mounted just within the upper end of said plug, 54. Preferably the opposite ends of said coiled spring 59 are protected and held in place by upper and lower cups 62 and 53 respectively.

Beginning at the lowermost level of the plunger guide l5 there are provided in said guide a plurality of longitudinally extending slots 64. These slots are shown in the drawing as being six 1n number, as that number gives suicient openings for the water to come through the said plunger guide into the well when the plunger begins to approach its upward position and from there on until the plunger gets to its upward position about as shown in Fig. 4. Preferably these slots will be of `rounding formation both at the top and bottom thereof so as to be free of any possible inwardly extending or cutting edge to wear or cut the rubber plunger cup 5l. The exact number of these slots is immaterial so long as there are enough of them and of large enough area to freely let the liquid pour through said slots as soon as the plunger cup has its lower edge above the lower end of the said slots. By having six slots of substantially the size shown in the drawings there is plenty ofv material or area as at 65 on the inside of the plunger guide to hold the plunger in its circular position and shape and the slots 64 are small,u enough in extent sidewise to prevent the ordinary plunger cup frombeing forced outwardly through the saidv slots when the plunger is taking a downward movement.

It will nowl be seen that when upward movement of the handle lever 29 brings the bottom edge of the skirt 52 of the plunger cup 5l slightly above the lower end of the slots 64 in the plunger guide l5, the liquid in the surrounding receptacle will begin to pour through the parts of the slots so uncovered and such pouring of the liquid through the slotswill continue as the further upwardmovement of the barrel and its attached plunger cup still further uncovers more of. the' length of the slots 64.

In Fig. 4 the, skirt portion 52 of saidv plunger cup is indicated at a. position approaching the ordinary upward movement of the barrel, as the pump is ordinarily operated by a person using only relatively short strokes. When the pump is. rst brought into action longer strokes may be taken so as to be sure that plenty of liquid drops into the well of the pump at each stroke, orv a very energetic person may take such relatively long strokes if he wishes. Part of the advantage of this form of pump however is that it adapts itself to the natural short strokes that an ordinary person takes to Work the pump easily. In such operation the raising, of the plunger to above the position shown in Fig. 4 is suflicient to keep the pump working in a satisfactory manner. On depressing the plunger and barrel by downward movement ofk the handle lever the skirt of the plunger cup soon covers the lower portion of the several slots 64v and thus prevents the escape of liquid out through these slots into the receptacle. Certainly from there on the further downward movement of the plunger cup positively connes the liquid in the well from escaping upward past the skirt of the plunger cup and so in an obvious manner the pressure upon the liquid in the well easily raises the valve ball 58 and thereupon the liquid rushes up past the barrel and through the main central passage of the plug 54. Ordinarily there will be more or less liquid in the barrel 2t and especially in its lower extension 45 so that the liquid caused to move up through the plug simply increases the amount of liquid in such barrel extension and in the barrel. I-lere again it will be noted that the pump will operate entirely satisfactorily even though it does not have its plunger nor barrel moved so far down to the downward position thereof as shown in Fig. 3. If the operator stops the downward stroke when the plunger is appreciably above the position shown in Fig. 3, the pumping action will be continued as long as the skirt of the plunger cup goes safely past the lower end of the longitudinal slots 64. in the plunger guide. Thek only result of such shorter strokes is that proportionately less liquid is forced up through the check valve and the well is accordingly left partly full of liquid against the next inflow of liquid through the slots 64.

As the plunger andV its barrel and barrel extension are all connected to move as a unit it will be seen that the real pumping action takes place when the liquid in the well is caught below the descending plunger. The downward movement of the plunger then forces the liquid up through the check valve and increases the amount of liquid in the lower part ofthe barrel and its extension and so adds to the air pressure in the body of air above the top of the liquid in said extension and the barrel. When the plunger is raisedit does not move relative to the barrel 2i).v and its extension` 45` butv moves with those parts and the check valve simply prevents the downward passage of liquid past said check valve when the plunger starts and moves upwardly. As the longitudinal slots 64 are again uncovered more liquid pours in due partly to the suction created by the upwardly moving plunger cup having created more or less of a vacuum in the well, then on the next recurring downward stroke the liquid again caught beneath the plunger cup is conned from escape except upward past the valve ball. It will be understood of course that the pocket of air under pressure in the upper part of the barrel 2o operates to force the liquid from the bottom. of the barrel up through the liquid pipe 42 and so to the hose 24,

It will be noted that I have described the skirt 52 of the plunger cup 5I as fitting against the inside of the well I3 and its aligned upwardly extending plunger guide I5, and also that the well and the said plunger guide are exteriorly somewhat smaller than the outside diameter of the larger main p-art 2B of the barrel which in turn slides through the collar 45. The purpose of this relative sizing of these parts is so that the said plunger cup may be drawn up from the well and said plunger guide through the said collar 46 at any time it is desired to repair or replace said plunger cup or any of its attached parts by simply removing the split pin or other fastening device at the left hand or inner end of the inwardly bent horizontal arm at the upper end of the connecting rod and removing said horizontal arm of the connecting rod from its horizontal hole 34 in the cap at the top of the barrel. In this way the barrel and its downward extension and its plunger cup can be moved upwardly as one unit through the opening of said collar and returned down therethrough.

Preferably there is provided on the upper side of the upwardly extending enlargement 39 on the cap 23 a vertically arranged screw-threaded hole 66, which opens into the horizontal port 40 and likewise opens in direct alignment with the vertical port 4I. Ordinarily this opening 66 is closed by a screw-threaded plug 6?. By removing this plug access is had through the port 4I and down into the bore of the liquid pipe 42, which connects with said vertical port 4I. By removing said plug a wire can be pushed down through the port 4I and through the liqui-d tube 42 to remove any sediment or obstruction that may have lodged in said pipe or in the port 4 I.

In the formation of the elongated slots 64 in the plunger guide I5 care will be taken to have the metal adjacent the edges of the slots turned outwardly very slightly, that is, just enough to be sure that there is no inwardly extending burr or protuberance that would wear upon the rubber plunger cup.

What I claim as new is:

1. In a knapsack sprayer pump the combination of a liquid holding receptacle having an apertured top with a vertically arranged collar bounding sai-d aperture, a closed well projecting downwardly below the bottom of the receptacle in alignment with said collar, a guide projecting upwardly from the top of the well and having its side wall in alignment with the well and having perforations in its lower part, a barrel reciprocatingly mounted in said top collar and having a lower extension of smaller diameter, a closure disc for the lower part of said extension spaced slightly up from its lower extremity and having its central portion thickened and provided with af central threaded aperture therein', a plunger cup having its downwardly extending skirt tting the inner wall of said well and guide, the diaphragm portion of said cup being mounted in the lower extremity of said barrel extension and bearing against the lower face of said closure disc and having a central hole registering with the hole in the disc, a centrally bored, bolt-like plug having its shank portion exteriorly threaded and fitting the threading of said aperture of the disc, the enlarged head of said plug bearing against the plunger cup adjacent the hole thereof and detachably holding the cup upon the barrel extension, the bore of said plug being smaller near its lower end and thus forming a valve seat, a valve ball in said bore intermediate in size between the two parts of the said plug bore and adapted to iit down upon said seat and close the same but adapted when raised therefrom to let liquid pass thereby up through the plug, means for yieldingly urging said ball valve down and for retaining it in the bore of the plug, an outlet for liquid at the top of the barrel and means for reciprocating said barrel.

2. In a knapsack sprayer pump the combination of a liquid holding receptacle having an apertured top with a vertically arranged circular collar bounding said aperture, a circular closed well projecting downwardly below the bottom of the receptacle and in alignment with said co1- lar, a circular guide projecting upwardly from the top of the well and having its side wall in alignment with the well and having perforations in its lower part, a circular barrel reciprocatingly mounted in said top collar and having a lower extension of smaller diameter, a closure disc for the lower part of said extension spaced slightly up from its lower extremity and having its central portion thickened and provided with a central threaded aperture therein, a plunger cup having its downwardly extending skirt tting the inner wall of said well and guide, the diaphragm portion of said cup being mounted in the lower extremity of said barrel extension and bearing against the lower face of said closure disc and having a central hole registering with the hole in the disc, a centrally bored, bolt-like plug having its shank portion exteriorly threaded and fitting the threading of said aperture of the disc, the enlarged head of said plug bearing against the plunger cup adjacent the hole thereof and detachably holding the cup upon the barrel extension, the bore of said plug being smaller near the lower end and thus forming a valve seat, a valve ball in said bore intermediate in size between the two parts of the said plug bore and adapted to fit down upon said seat and close the same but adapted when raised therefrom to let liquid pass thereby up through the plug, means for yieldingly urging said ball valve down and for retaining it in the bore of the plug, an outlet for liquid at the top of the barrel and means for reciprocating said barrel.

3. In a knapsack sprayer pump the combination of a liquid holding receptacle having an apertured top with a vertically arranged circular collar bounding said aperture, a circular closed well projecting downwardly below the bottom of the receptacle and in alignment with Said collar, a circular guide projecting upwardly from the top of the well and having its side wall in alignment with the well and having perforations in its lower part, a circular barrel reciprocatingly mounted in said top collar and having a lower extension of smaller diameter, a closure disc for the lower part of said extension spaced slightly up from its lower extremity and having its central portion thickened and provided with a central threaded aperture therein, a plunger cup having its downwardly extending skirt :Fitting the inner wall of said well and guide, the diaphragm portion of said cup being mounted in the lower extremity of said barrel extension and bearing against the lower face of said closure disc and having a central hole registering with the hole in the disc, a centrally bored, bolt-like plug having its shank portion exteriorly threaded and tting the threading of said aperture of the disc, the enlarged head of said plug bearing against the plunger cup adjacent the hole thereof and detachably holding the cup upon the barrel extension, the bore of said plug being smaller near its lower end and thus forming a valve seat, a valve ball in said bore intermediate in size between the two parts of the said plug bore and adapted to fit down upon said seat and close the same but adapted when raised therefrom to let liquid pass thereby up through the plug, means for yieldingly urging said ball Valve down and for retaining it in the bore of the plug, an outlet for liquid at the top of the barrel, a liquid tube extending from near the lower end of the larger part of the barrel up to said liquid outlet and means for reciprocating said barrel.

4. In a knapsack sprayer pump the combination of a liquid holding receptacle having an apertured top with a vertically arranged circular collar bounding said aperture, a circular closed well projecting downwardly below the bottom of the receptacle and in alignment with said collar,

a circular guide projecting upwardly from the top of the well and having its side wall in alignment with the well and having perforations in its lower part, a circular barrel reciprocatingly mounted in said top collar and having a lower extension of smaller diameter, a closure disc for the lower part of said extension spaced slightly up from its lower extremity and having its central portion thickened and provided with a central threaded aperture therein, a plunger cup having its downwardly extending skirt tting the inner wall of said well and guide, the diaphragm portion of said cup being mounted in the lower extremity of Said barrel extension and bearing against the lower face of said closure dise and having a central hole registering with the hole in the disc, a centrally bored, bolt-like plug having its shank portion exteriorly threaded and tting the threading of said aperture of the disc, the enlarged head of said plug bearing against the plunger cup adjacent the hole thereof and detachably holding the cup upon the barrel extension, the bore of said plug being smaller near its lower end and thus forming a valve seat, a valve ball in said bore intermediate in size between the two parts of the said plug bore and adapted to t down upon said seat and close the same but adapted when raised therefrom to let liquid pass thereby up through the plug, means for retaining said ball in the bore of the plug, an outlet for liquid at the top of the barrel, a liquid tube extending from near the lower end of the larger part of the barrel up to said liquid outlet and means for reciprocating said barrel.

MYRON H. SMITH. 

